As it is known, when washing surfaces such as for example windows, walls, floors, metal panels and the like, it is necessary to use brushes, cloths or the like together with the application of detergent substances mixed in water.
Moreover, in performing these operations it is known to use pressure cleaner brushes, which comprise a half-shell inside which there is a bladed impeller, which is driven by a jet of water and transmits motion to a rotating brush that protrudes from said half-shell.
Transmission of motion between the impeller and the rotating brush is commonly obtained by direct keying on said shaft or by interposing conventional gear systems, which generally allow to reduce the rotation rate between the driving wheel and the driven wheel.
The jet of water that propels the vanes of the impeller conventionally arrives from a nozzle, which is arranged in the peripheral region of the half-shell and is connected to a rigid tube, which is designed to act as a handle and to the free end of which a generic water supply system can be connected.
In order to facilitate the user in the washing operations, known types of pressure cleaner brush have tablets or the like made of soap or other similar substances, which are introduced in a receptacle provided inside the rigid tube, so that during use they are affected by the incoming water stream.
This solution allows to break down the detergent substances contained in the tablets and to transfer them directly into the washing water that passes through the pressure cleaner brush, allowing the user to perform cleaning operations without resorting separately to the use of external detergents.
These known types of pressure cleaner brush, however, are not free from drawbacks, including the fact that they do not allow to adjust the introduction and dissolving of the detergent substances in the washing water.
In particular, it is noted that these brushes are not suitable to be used, for example, to rinse soap-lathered surfaces, since they do not provide for operation with only water flowing out, unless the tablets contained in them are used up completely.
Moreover, the tablets significantly affect the production and operating costs of conventional pressure cleaner brushes, and this is due to the specifications required for their insertion in the tube of said brushes.
Moreover, there is no possibility to use detergents other than tablets, such as for example commercial ones, which are far cheaper.
Another drawback affects known types of pressure cleaner brush that transmit motion from the impeller to the rotating brush by direct keying; while on the one hand this transmission allows the rotating brush to turn at high speeds, on the other hand it does not allow to give said brush enough torque for efficient operation.
More specifically, the rotating brush is not able to apply a force that is sufficient to overcome even the modest resistance offered by edges or uneven surfaces encountered by said brush during normal cleaning operations, and is disadvantageously subjected to alternating operation with frequent stops.
Transmission of motion by means of the conventional gear systems currently in use, instead, allows to reduce the rotation rate of the rotating brush, transmitting a higher torque to it; at the same time, however, said transmission is significantly bulky.